BASIC stamp manual v2.2

5: BASIC Stamp Command Reference – SEROUT
BASIC Stamp Syntax and Reference Manual 2.2 www.parallax.com Page 427
Figure 5.41: SEROUT Open-
Source Circuit. This circuit is for
use with the Open, Inverted
baudmode.
BASIC
Stamp
Vss
I/O
Pin
Gnd
(Vss)
BASIC
Stamp
I/O
Pin
Gnd
(Vss)
To o t h er
devices
To o th er
devices
1 k
Serial communication, because of its complexity, can be very difficult to
work with at times. Please follow these guidelines (and those in the
"SERIN Troubleshooting" section of the SERIN command description)
when developing a project using the SERIN and SEROUT commands:
1. Always build your project in steps.
a. Start with small, manageable pieces of code, that deals with
serial communication) and test them, one at a time.
b. Add more and more small pieces, testing them each time, as
you go.
c. Never write a large portion of code that works with serial
communication without testing its smallest workable pieces
first.
2. Pay attention to timing.
a. Be very careful to calculate and overestimate the amount of
time operations should take within the BASIC Stamp.
Misunderstanding the timing constraints is the source of most
problems with code that communicate serially.
b. If the serial communication in your project is bi-directional,
the above statement is even more critical.
3. Pay attention to wiring.
a. Take extra time to study and verify serial communication
wiring diagrams. A mistake in wiring can cause strange
problems in communication, or no communication at all.
Make sure to connect the ground pins (Vss) between the
devices that are communicating serially.
4. Verify port setting on the PC and in the SERIN/SEROUT
commands.
SEROUT
TROUBLESHOOTING.